Anatomy, pathophysiology and classification of posterior tibial tendon dysfunction.

OBJECTIVE: Adult acquired flatfoot deformity is generally associated with a collapsing medial longitudinal arch and a progressive loss of strength of the posterior tibial tendon (PTT). This condition is commonly associated with PTT dysfunction or rupture, which can have an arthritic or a traumatic etiology. Several causes have been proposed to explain the clinical evidence of tendon degeneration observed at the time of surgery including trauma, anatomical, mechanical, inflammatory and ischemic factors. MATERIALS AND METHODS: In this review, we analyzed anatomy, pathophysiology and existing classifications of posterior tibial tendon dysfunction. RESULTS: Anatomical features, and in particular vascularization, expose PTT to major degenerative disorders until rupture. A literature overview showed that a low blood supply of the gliding part of the tendon is linked to a dysfunction and/or a rupture of the PTT in the region located behind the medial malleolus. CONCLUSIONS: PTT low blood supply causes a dysfunction resulting in an abnormal loading of the foot's medial structures. This may be the reason why PTT dysfunction leads to an acquired flatfoot deformity. Conversely, flatfoot deformity may be a predisposing factor for the onset of PTT dysfunction.

Amniotic fluid stem cells: an ideal resource for therapeutic application in bone tissue engineering.

OBJECTIVE: Skeletal diseases, both degenerative and secondary to trauma, infections or tumors, represent an ideal target for regenerative medicine and in the last years, stem cells have been considered as good candidates for in vitro and in vivo bone regeneration. To date, several stem cell sources, such as adult mesenchymal stem cells, embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), have shown significant osteogenic potential. MATERIALS AND METHODS: In this narrative review, we analyze the possible advantages of the use of AFSCs in the treatment of skeletal diseases, especially through the application of tissue engineering and biomaterials. RESULTS: Among the different sources of stem cells, great attention has been recently devoted to amniotic fluid-derived stem cells (AFSC) characterized by high renewal capacity and ability to differentiate along several different lineages. CONCLUSIONS: Due to these features, AFSCs represent an interesting model for regenerative medicine, also considering their low immunogenicity and the absence of tumor formation after transplantation in nude mice.

Groin Pain Syndrome Italian Consensus Conference on terminology, clinical evaluation and imaging assessment in groin pain in athlete.

The nomenclature and the lack of consensus of clinical evaluation and imaging assessment in groin pain generate significant confusion in this field. The Groin Pain Syndrome Italian Consensus Conference has been organised in order to prepare a consensus document regarding taxonomy, clinical evaluation and imaging assessment for groin pain. A 1-day Consensus Conference was organised on 5 February 2016, in Milan (Italy). 41 Italian experts with different backgrounds participated in the discussion. A consensus document previously drafted was discussed, eventually modified, and finally approved by all members of the Consensus Conference. Unanimous consensus was reached concerning: (1) taxonomy (2) clinical evaluation and (3) imaging assessment. The synthesis of these 3 points is included in this paper. The Groin Pain Syndrome Italian Consensus Conference reached a consensus on three main points concerning the groin pain syndrome assessment, in an attempt to clarify this challenging medical problem.

CROSSTALK BETWEEN VITAMIN B AND IMMUNITY.

Vitamin B1 (thiamin) is considered to be the oldest vitamin and in 1936 R.R. Williams and colleagues determined its chemical structure and were able to synthesize this vitamin. Vitamin B1 influences pro-apoptotic proteins, mitochondrial membrane potential, cytochrome C release, protein kinases, p38-MAPK, suppresses oxidative stress-induced NF-kappaB and has anti-inflammatory properties. Deficiency of vitamin B1 may cause beriberi, dysfunction of the nervous system, neuroinflammation, T cell infiltration, chemokine CCL2 activation, over expression of proinflammatory cytokines, such as IL-1, TNF, IL-6, and arachidonic acid products, and induces expression of CD40 by the microglia and CD40L by astrocytes which provoke the death of neurons. Here we report the relationship between vitamin B complex and immunity.

Can vitamin a mediate immunity and inflammation?

Vitamins are natural components of foods and are organic compounds distinct from fat, carbohydrates and proteins. Vitamin A is the generic descriptor for compounds with the qualitative biological activity of retinol. Unlike beta-carotene, vitamin A is not an antioxidant and its benefit is related to possible boosting of immune reactions. The effect of vitamin A on immune function is wide-reaching and its deficiency appears to affect immunity in several ways. Innate and adaptive immune responses are affected in some way by lack of vitamin A. Retinoids seem to act on differentiation of lymphocytes, antibody production, phagocytosis of macrophages, NK, Treg, and T helper cell activity. In addition, in humans, signs of a vitamin A deficiency also include the dysregulation of cytokine/chemokine generation and release. However, excess of vitamin A has been demonstrated to have toxic effects in most species studied. Here we summarize some important effects of vitamin A in immunity and inflammation.

Relationship between serotonin and mast cells: inhibitory effect of anti-serotonin.

Serotonin (5-HT) is an important neurotransmitter that acts in both central and peripheral nervous system, and has an impact on cell proliferation, migration and apoptosis. 5HT exerts its effects via several receptors. Treatment with anti-5-HT receptors diminish the severity of contact allergy in experimental animals, an effect mediated by mast cells; while an agonist reduces the stress level and relieves pruritus in patients with atopic dermatitis. Mast cells are important for both innate and adaptive immunity and they are activated by cross-linking of FceRI molecules, which are involved in the binding of multivalent antigens to the attached IgE molecules, resulting in a variety of responses including the immediate release of potent inflammatory mediators. Serotonin is present in murine mucosal mast cells and some authors reported that human mast cells may also contain serotonin, especially in subjects with mastocytosis. Here we report the interrelationship between mast cells, serotonin and its receptor inhibitor.

Impact of mast cells on multiple sclerosis: inhibitory effect of natalizumab.

Mast cells (MCs) derive from a distinct precursor in the bone marrow and are predominantly found in tissues at the interface between the host and the external environment where they can secrete mediators without overt degranulation. Mast cells mature under local tissue microenvironmental factors and are necessary for the development of allergic reactions, through crosslinking of their surface receptors for IgE (FcεRI), leading to degranulation and the release of vasoactive, pro-inflammatory and nociceptive mediators that include histamine, pro-inflammatory and anti-inflammatory cytokines and proteolytic enzymes. Multiple sclerosis (MS) is an autoimmune disease characterized by inflammatory demylination within the central nervous system. MCs are involved in the pathogenesis of MS by generating various vasoactive mediators and cytokines and participate in the destruction of the myelin sheath and the neuronal cells. The process of the development of demyelinating plaques in MS is probably linked with the rupture of the blood-brain barrier by MC products. The effects of natalizumab, which is a very effective drug in reducing the annualized relapse rate and other relapse-based endpoints, are discussed. Here, we report the relationship between MCs and MS.

Corticotropin-releasing hormone, microglia and mental disorders.

Microglia derive from mononuclear myeloid progenitors and are a major glial complement of the central nervous system. When microglia are activated they secrete inflammatory cytokines and toxic mediators which amplify the inflammatory response. In addition, the microglia inflammatory products are implicated in the neuronal destruction usually observed in various neurodegenerative diseases. Microglia cells express corticotropin releasing hormone (CRH) receptors, and activation of microglia by CRH releases bioactive molecules which have a biological effect in the brain and regulate several neurological diseases. CRH plays a pivotal role in stress responses and is a key mediator of the hypothalamic-pituitary-adrenocortical system. CRH is expressed in human mast cells, leading to autocrine effects and participates in inflammatory response together with neuropeptides, and stimulates mast cells. IL-33-activated mast cells release vascular endothelial growth factor in response to CRH and act synergistically to increase vascular permeability. CRH also up-regulates IL-18 expression by increasing intracellular reactive oxygen in microglia cells. Here we report the relationship between CRH, microglia and mental disorders.

Neuropeptide NGF mediates neuro-immune response and inflammation through mast cell activation.

Human mast cells (first described in 1879 by Paul Ehrlich) develop from committed precursors in the bone marrow expressing the differentiation marker CD34+ and distinct from the three other myeloid cells. Mast cells are present in various tissues especially near blood vessels, epithelia and nerves and they are activated by cross-linking of FcεRI, but also by a number of neuropeptides. NGF mediates a number of inflammatory and autoimmune states in conjunction with an increased accumulation of mast cells which appear to be involved in neuroimmune interactions and tissue inflammation. Here we report some relationships between mast cells and nerve growth factor (NGF).

Interrelationship between IL-3 and mast cells.

It is well established that mast cells, which are found in the tissues in the proximity of small blood vessels and post-capillary venules, play a key role in the early phase of IgE-mediated allergic reactions. A greatly expanded understanding of the biology of IL-3 has emerged since the early 1980s. IL-3 is a specific factor that stimulates the growth of hematopoietic stem and progenitor cells of a variety of lineages and can promote the proliferation of certain classes of lymphocytes distinct from those that are dependent on IL-2. IL-3 has been identified among the most important cytokines for regulation of mast cell growth and differentiation, migration and effector function activities of many hematopoietic cells. IL-3 termed multi colony-stimulating-factor (multi-CSF) or mast cell growth factor (MCGF) is a haematopoietic growth factor which stimulates the formation of colonies for erythroid, megakaryocytic, granulocytic and monocytic lineages. It is predominantly produced by activated T cells, natural killer (NK) cells and mast cells and supports the growth-promoting effects of SCF on mast cell precursors. IL-3 causes severe hypersensivity reactions and plays a pivotal role in exacerbating the inflammatory response in vivo. Here we report the interrelationship between IL-3 and mast cells.

Nerve growth factor interactions with mast cells.

Neuropeptides are involved in neurogenic inflammation where there is vasodilation and plasma protein extravasion in response to this stimulus. Nerve growth factor (NGF), identified by Rita Levi Montalcini, is a neurotrophin family compound which is important for survival of nociceptive neurons during their development. Therefore, NGF is an important neuropeptide which mediates the development and functions of the central and peripheral nervous system. It also exerts its proinflammatory action, not only on mast cells but also in B and T cells, neutrophils and eosinophils. Human mast cells can be activated by neuropeptides to release potent mediators of inflammation, and they are found throughout the body, especially near blood vessels, epithelial tissue and nerves. Mast cells generate and release NGF after degranulation and they are involved in iperalgesia, neuroimmune interactions and tissue inflammation. NGF is also a potent degranulation factor for mast cells in vitro and in vivo, promoting differentiation and maturation of these cells and their precursor, acting as a co-factor with interleukin-3. In conclusion, these studies are focused on cross-talk between neuropeptide NGF and inflammatory mast cells.

Role of mast cells in atherosclerosis: a classical inflammatory disease.

Atherosclerosis is an inflammatory disease and hyperlipidaemia is one of the main risk factors for aging, hypertension and diabetes. Variance in plasma LDL cholesterol concentration may be associated with differences in cardiovascular disease risk and high levels of lipids are associated with increased risk of developing atherosclerosis. Macrophages, which generate pro-inflammatory cytokines, mainly interleukin-1 (IL-1) and tumor necrosis factor-α (TNF-alpha), are deeply involved in atherosclerosis, as well as mast cells which generate several cytokines, including IL-6 and IFN-gamma, and chemokines such as eotaxin, MCP-1 and RANTES involved in monocyte recruitment and differentiation in the arterial wall. In addition, mast cells participate in lipid retention and vascular cell remodeling, and are mediators of innate and adaptive immunity during atherosclerosis. Mast cells which accumulate in the human arterial intima and adventitia during atherosclerotic plaque progression, release vasoactive and angiogenic compounds, and pro-inflammatory mediators, such as arachidonic acid metabolites, histamine, cytokines/chemokines, platelet activating factor (PAF) and proteolytic enzymes. Mast cells can be activated by pro-inflammatory stimuli, including cytokines, hypercholesterolemia, and hyperglycemia, and trigger the endothelial expression of adhesion molecules such as P-selection, vascular cell adhesion molecule-1 (VCAM-1) and chemokines which mediate the recruitment and adhesion of leukocytes. The participation of mast cells in atherosclerosis is still an enigma and it may be of therapeutic interest to clarify this process.

Impact of mast cells on the skin.

When through the skin a foreign antigen enters it provokes an immune response and inflammatory reaction. Mast cells are located around small vessels that are involved in vasaldilation. They mature under the influence of local tissue to various cytokines. Human skin mast cells play an essential role in diverse physiological and pathological processes and mediate immediate hypersensitive reaction and allergic diseases. Injection of anti-IgE in the skin or other agents that directly activate mast cells may cause the decrease in vascular tone, leakage of plasma and may lead to a fall in blood pressure with fatal anaphylactic shock. Skin mast cells are also implicated as effector cells in response to multiple parasites such as Leishmania which is primarily characterized by its tissue cutaneous tropism. Activated macrophages by IFNgamma, cytotoxic T cells, activated mast cells and several cytokines are involved in the elimination of the parasites and immunoprotection. IL-33 is one of the latest cytokines involved in IgE-induced anaphylaxis and in the pathogenesis of allergic skin disorders. IL-33 has been shown in epidermis of patients with psoriasis and its skin expression causes atopic dermatitis and it is crucial for the development of this disease. Here we review the impact of mast cells on the skin.

Mast cell involvement in rheumatoid arthritis.

Autoimmunity is a failure of self-tolerance resulting in immune reactions against autologous antigen. Rheumatoid arthritis is characterized by inflammation of synovium associated with destruction of the join cartilage and bone. A role of mast cell-mediated inflammation and antibodies are involved in this disease. Numerous cytokines such as IL-1, TNF, IL-8, IL-33 and IFN gamma have been implicated in rheumatoid arthritis and in particular in the synovial joint fluid. Since TNF is believed to activates resident synovial cells to produce collagenase that mediate destruction of cartilage, antagonists against the inflammatory cytokine TNF have a beneficial effects in this disease. Here we review the interrelationship between rheumatoid arthritis and mast cell activation.

Impact of capsaicin on mast cell inflammation.

Mast cells are inflammatory cells, and they are prominent in inflammatory diseases such as allergy and asthma. Mast cells possess high-affinity receptors for IgE (FcERI) and the cross-linking of these receptors is essential to trigger the secretion of granules containing arachidonic acid metabolism (such as prostaglandin (PG) D2, leukotriene (LT) B4, and LTC4), histamine, cytokines, chemokines, and proteases, including mast cell-specific chymases and tryptases. Activation of mast cells provokes the secretion of cytokines and mediators that are responsible for the pathologic reaction of immediate hypersensitivity. Sensory nerve stimulation by irritants and other inflammatory mediators provokes the release of neuropeptides, causing an increase in vascular permeability, plasma extravasation and edema. Trigeminal nerve stimulation actives dura mast cells and increases vascular permeability, effects inhibited by capsaicin. Capsaicin causes release of sensory neuropeptide, catecholamines and vasodilation. Several studies have reported that capsaicin is effective in relief and prevention of migraine headaches, improves digestion, helps to prevent heart disease, and lowers blood cholesterol and blood pressure levels. The findings reported in these studies may have implications for the pathophysiology and possible therapy of neuroinflammatory disorders.

Role of vitamins D, E and C in immunity and inflammation.

Inflammatory responses are operationally characterized by pain, redness, heat and swelling at the site of infection and trauma. Mast cells reside near small blood vessels and, when activated, release potent mediators involved in allergy and inflammation. Vitamin D modulates contraction, inflammation and remodeling tissue. Vitamin D deficiency has been linked to multiple diseases and several data have demonstrated a strong relationship between serum vitamin D levels and tissue function. Therapy targeting vitamin D3 signaling may provide new approaches for infectious and inflammatory skin diseases by affecting both innate and adaptive immune functions. Mast cells are activated by oxidized lipoproteins, resulting in increased expression of inflammatory cytokines and suggesting that the reduction of oxidation of low density lipoprotein by vitamin E may also reduce mast cell activation. Vitamin C is also an anti-oxidant well-known as an anti-scurvy agent in humans. Vitamin C inhibits peroxidation of membrane phospholipids and acts as a scavenger of free radicals and is also required for the synthesis of several hormones and neurotransmitters. In humans, vitamin C reduces the duration of common cold symptoms, even if its effect is not clear. Supplementation of vitamin C improves the function of the human immune system, such as antimicrobial and natural killer cell activities, lymphocyte proliferation, chemotaxis and delayed-type hypersensitivity. Vitamin C depletion has been correlated with histaminemia which has been shown to damage endothelial-dependent vasodilation. However, the impact of these vitamins on allergy and inflammation is still not well understood.

Vascular endothelial growth factor (VEGF), mast cells and inflammation.

Vascular endothelial growth factor (VEGF) is one of the most important inducers of angiogenesis, therefore blocking angiogenesis has led to great promise in the treatment of various cancers and inflammatory diseases. VEGF, expressed in response to soluble mediators such as cytokines and growth factors, is important in the physiological development of blood vessels as well as development of vessels in tumors. In cancer patients VEGF levels are increased, and the expression of VEGF is associated with poor prognosis in diseases. VEGF is a mediator of angiogenesis and inflammation which are closely integrated processes in a number of physiological and pathological conditions including obesity, psoriasis, autoimmune diseases and tumor. Mast cells can be activated by anti-IgE to release potent mediators of inflammation and can also respond to bacterial or viral antigens, cytokines, growth factors and hormones, leading to differential release of distinct mediators without degranulation. Substance P strongly induces VEGF in mast cells, and IL-33 contributes to the stimulation and release of VEGF in human mast cells in a dose-dependent manner and acts synergistically in combination with Substance P. Here we report a strong link between VEGF and mast cells and we depict their role in inflammation and immunity.

Luteolin inhibits mast cell-mediated allergic inflammation.

Mast cells are ubiquitous in the body and multifunctional immune cells; they are known to be primary responders in allergic reactions, orchestrating strong responses to minute amounts of allergens. Mature mast cells perform important beneficial roles in host defense, both in IgE-dependent immune responses to certain parasites and in natural immunity to bacterial infection. In IgE-associated biological responses, the crosslinking of FcεRI-bound IgE with multivalent antigens initiate the activation of mast cells by promoting aggregation of FceRI. This cross-linking receptor-bound IgE by multivalent Ag initiates a cascade of intracellular reactions leading to mediator release such as proinflammatory mediators, chemokines and cytokines. Luteolin belongs to a flavone group of compounds called flavonoids, it has anti-oxidant properties, inhibits some cancer cell proliferation and exerts a regulatory effect on mast cell-mediated inflammatory diseases and allergy. Here we report the impact of luteolin on mast cell activation.

First case report of vanadium metallosis after ceramic-on-ceramic total hip arthroplasty.

The development of metallosis as a complication following rupture of a hip replacement is known to occur as a result of contact with metal components of the prosthesis (1).In such cases, high cobalt (Co), chromium (Cr) and molybdenum (Mo) levels in the blood have been reported by several Authors (2).Recently, it has been stressed that the clinical investigation should focus on general reactions to high circulating metal levels, such as toxicity for the central nervous system (CNS) and the immune system (3).Despite the increasing interest of literature in ceramic-on-ceramic hip arthroplasty (4),little is known about these complications, and in particular of metallosis. To our knowledge this is the first description of a condition of extensive metallosis and radiographic signs presenting as a result of wear of a ceramic-on-ceramic prosthesis.